Electric signaling



SSheets-Sheet 1 INVENTOR R l. L. HARTLEY JN y 5 k R. V. L. HARTLEY ELECTRIC SIGNALING Filed June 27. 1942 March 21, 1944.

ATTORNEY 3 Sheets-Sheet 2 lNl/E/VTOR R. ML. HARTLEY ATTORNEY March 21, 194 R. v. 1.. HARTLEY ELECTRIC SIGNALING Filed June 27, 1942 \J\'/ 2 w m 000000000 000000 00000000000000 3 F 00000 0 00 0 0000000 000 0 00000 s 00 0 0000 4 m 00 0 000 G 00 0 000 H 00 0 00 00 0 0 00 a 000 000 0 00 m 000000000000000 00 0000 0000 000000 00 00 000 0 00 00 0 0 0 0 0 0 0 0 0 0 M O (I{\\II0L G HVQ 0000000000? 0i 0 0000000000000000 0000 000 m 000000000000 0 0 2 00000000000 0 0 00000000000 0 0 5 00000000000 0 0 m 00000000000 0 00 ,7 000000000000 0 00 4 a 000000000000 00 000 7 0000000000000 00 000 M 00 00000000000000 00000 0000 1 M 0000000000000000 00000000000000 P 0 H N H w n q m 0 9 March 21, 1944. R. v. HARTLEY ELECTRIC SIGNALING Filed June 27, 1942 3 Sheets-Sheet 5 TENS HUNDREDS THOUSANDS INVENTOR By R L L. HARTLD" ATTORNE V Patented Mar. 21, 1944 UNITED STATES. PATENT OFFICE ELECTRIC SIGNALING Ralph V. L. Hartley, Summit, N. 1., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application June 27, 1942, SerialNo. 448,735 7.. v I

1 Claims. (01. 179-27 r a This invention relates to electric signaling,

particularly when employed in connection with the operation of automatic telephone systems.

An object of the inventionis to facilitate the identification of lines trunks, or other electric circuits or devices.

A more specific object is to reduce the amount of equipment needed for identifying the lines of a large group by providing a field oi lamps representing the lines and utilizing a simple scanning process to determine the designation of any desired line from the position of the corresponding lamp in the field.

Another object of the invention is to identify the lines of a group by the use of an electron beam for scanning a field of lamps or similar elements representative of the lines of the group.

These objects are realized in a system for identifying the individual lines of a large group, such as the lines in a telephone system, by means of a field or array of signal lamps which are individual respectively to the lines of the group and which are arranged in decimal order in coordinate rows, together with means for scanning the array of signal lamps to determine the location of a lighted lamp therein. More specifically the field of lighted lamps is scanned byv a scanning beam in a definite order relative to the decimal arrangement of the lamps in the field; and at the same time the beams of a plurality of switching devices, representing respectively the several digital places of the designations, are driven through a succession of switching positions to select the different values of the digits in the corresponding digital places. The rates at which these switching beams are driven through their switching positions are related to the movement of the scanning beam over the field of lamps such that they occupy at any instant the positions representing the digital place values of the designation of the line corresponding to the particular lamp being scanned at that instant by the scanning beam If the lamp being scanned is in a lighted condition, the electron switching beams become efiective at that instant and cause the operation of associated registers to register the several digits of the corresponding line designation.

Another feature of the invention is an identification system in which the field of signal lamps is scanned by a movable screen to determine the relative position of a lighted lamp in the field. More specifically, the lamps are arranged in horizontal and vertical rows in an order bearing a definite relation to the designations oi the lines they represent, and a screen having light-transmitting openings therein is advanced across the field of lamps in successive movements to determine first the horizontal position of any particular lighted lamp and then the vertical position thereof. Switching devices moving in synchronous relation with the scanning screen serve to select circuits for the operation of registers in accordance with each successive position of the screemand light-sensitive means controlled by the screen and cooperating with said switching devices serves to effect the operation of said registers over the selected circuits when the position of any lighted lamp in the field is located by said screen.

Other features of the invention will be described more fully in the following detailed specification.

In the drawings accompanying the specification:

Fig. 1 is a conventional diagram of an automatic telephone system arranged for calling line identification;

Fig. 2 illustrates the field or panel of lamps representing the subscriber's lines in an ofllce and serving to identify the lines by their numbers;

Fig. 3 discloses an alternative form of the line identifying mechanism; and

Fig. 4 illustrates the scanning system in which the mechanism of Fig. 3 is used.

The present invention is particularly useful in systems that require the preparation of tickets for the purpose of assessing a calling telephone subscriber for conversations held with other subscribers. Since these tickets are prepared automatically, it is necessary to determine the number of the calling line automatically in order that the charge may be assessed against the proper party. However, the invention may be used in any type of system where it is desirable to determine automatically the identity of a line, trunk, circuit, or other device. For example, it is often desirable to display the num- Referring to Fig. 1 of the drawings, the automatic telephone system illustrated herein comprises a large group of line's, usually ten thou sand, which appear in the telephone central o ifice in non-numerical switches such as finder switches. The line I illustrated in the drawing appears in the bank of line finder switch 1" which in turn is associated with a first selector switch 5. The selector 8 may have direct access to outgoing trunks or, as shown, it may have access through a succeeding selector switch s-l to these outgoing trunks, such as the trunk IOI, extending to distant omces.

The designation or identity of each line that establishes a toll call over one of the outgoing trunks IN is obtained by scanning a field oi signaling lamps mounted in a panel I02. This field of signal lamps includes a lamp for each of the ten thousand lines in the ofllce, and each lamp represents the number of the associated line. The lamps are arranged in decimal order in coordinate horizontal and vertical rows, there being 100 hundred horizontal rows and one hundred vertical rows, each row in both directions containing one hundred lamps.

Referring for the moment to Fig. 2, which illustrates the lamp formation more clearly, the hundred horizontal rows are divided into ten equal groups, one for each thousand lines. For example, the horizontal group of lamps 200 represents the No. 0 thousands group of lines, the horizontal group of lamps I represents the No. 9 thousands group of lines, and the eight intermediate groups of lamps not shown in the drawings represent the corresponding thousands groups. Each one of these thousands groups contains ten horizontal rows of one hundred lamps representing respectively the ten hundreds groups in the thousand. In like manner the field oi lamps. is divided into ten vertical groups representing the ten tens groups of all hundreds groups. For example, vertical groups 202 and 203 represent respectively the No. 0 and No. 9 tens groups. Each of these tens groups contains ten vertical rows of lamps representing respectively the ten units designations.

Returning to Fig. 1, the lamp field I02 is scanned by means of a scanning device I03'to determine the location therein oi any lighted lamp, To this end an image of the lamp field I02 is iocussed on the screen I04 of the scanning device by any suitable lens I05, and an electron beam is caused to play over the screen I04 under the control of a sweep circuit I 08. The sweep circuit I00 is energized by a suitable source of alternating current I01 and, by means of the control plates I00, I09, causes the electron beam to scan the image screen I04 in any desired pattern. It may be assumed, for example, that the electron beam is caused to traverse the virtual image of the lamp field I02 beginning with the first lamp in the No. 0 tens group, in the No. 0 hundreds group of the No. 0 thousand and passing over the horizontal one hundred-lamp rows in succession and in the same order until the last lamp in the No. 9

tens group of the No. 9 hundreds of the No. 9 thousand is reached. The scanning device I03, the lens system therefor, and the controlling sweep circuit I00 may be of any well-known type.

The position at any instant of the electron beam on the image screen I 04 in terms of the designation digits of the line represented by the lamp in the corresponding position in the panel I02 is determined by a set of rotary electron beam switching tubes III, III, H2 and H3, there being one of these tubes for each digital place in the designations of the lines. The tube IIO, which determines the values of the thousands digits,

contains a central cathode I ll, 0. control grid II! and a series of ten circumierentially placed anodes, one for each of the ten different values of the digit. The energizing coils H8, Ill, Ill and Ill located in quadrature around the tube III serve to produce a rotating field causing the beam from the central cathode Ill to sweep over the circumferential anodes at a speed depending upon the frequency of the energizing source. Similarly, the tubes I I I, H2 and H3, which determine respectively the values of the hundreds, tens and units digits, contain central cathodes I20, I2I, I22, control grids I22, I24, I25, and circumierentially located anodes, the same as tube I I0, representing the ten diflerent values of the corresponding digits. The tubes III, H2 and III also have the quadrature coils for producing the rotating field that causes the associated beams to sweep over the anodes. For a better understanding of the structure and operation of a tube or this character reference is made to the patent to Skellett, No. 2,217,774 oi. October 15, 1940.

The switching beam of the thousands tube III is driven in synchronism with the scanning beam. That is to say, the beam of tube IIO makes one complete rotation over the ten anode positions while the scanning beam is performing a complete scanning cycle of the screen I04. More specifically, the beam of the thousands tube H0 is in engagement with the No. 0 anode I28 during the interval that the scanning beam is scanning the image of the No. 0 thousands group of lamps; the beam is in engagement with the No. 1 anode I21 during the interval that the scanning beam is scanning the image of the No. 1 thousands group of lamps; and the same synchronous relation prevails throughout the remainder of the scanning cycle. This relation between the scanning beam and the rotating beam of the thousands tube I I0 is obtained by energizing the quadrature coils H6, II I, H8 and H9 with current taken directly from the source I01 and having, therefore, the same frequency. The phase divider I20 serves the well-known purpose of supplying the quadrature coils with current of two different phases for producing the necessary rotating magnetic field.

The switching beam of the hundreds tube III is also driven in synchronism with, the scanning beam but at a rate that is ten times as fast as that of the thousands beam I I0. In other words, the beam of tube I I I makes one complet revolution through its ten anode positions during the interval that the beam of tube H0 is in engagement with each one of its ten anodes. The synchronous relation between the beam 01' tub III and the scanning beam may be better understood from an examination of Fig. 2. Assuming that the scanning beam has just commenced a new cycle, it proceeds to scan over each of the ten horizontal hundreds rows of the No. 0 thousand group in succession. During the interval the scanning beam is traversing the No. 0 hundreds row in the thousand, the beam of tube III is dwelling on the No. 0 anode I 29; while the scanning beam is passing over the next or No. 1 hundreds row the beam of tube II I is in engagement with the next anode I30; and so on for each of the remaining eight hundreds rows. After the scanning beam has completed the scanning of the ten hundreds of the No. 0 thousand, it proceeds likewise to scan the corresponding ten hundreds of the No. 1 thousand, and the beam of tube III correspondingly repeats its cycle. And the same relation continues for the remaining thousands groups. The synchronous relation between the tube III and the scanning device I03 is obtained by driving the tube I I I from the same source I01; and the one-to-ten speed ratio between tubes I I and III is obtained by introducing a'frequency multiplier III which increases by ten times the frequency of the wave derived from the source I01. The output circuit of the frequency multiplier I 3| is applied to the phase divider I32, and the energy from the divider I32 is applied to the quadrature coils I33, I30, I35 and I30 to rotate the beam of tube III at the desired speed.

The switching beam of the tens tube I I2 is also driven in synchronism with the scanning device but at a frequency'which is ten times the frequency of the tube III. Since the speed ratio of the tubes I I I and I I2 is one to ten, it will be seen from Fig. 2 that the beam of tube II2 makes one complete revolution while the scanning beam is passing over a row of one hundred lamp images in any given thousand. The hundreds row being dividedinto ten tens groups, 202, 203, etc., it follows that the beam of tube H2 is engaging the No. 0 anode I31 while the scanning beam is passing over the ten positions in the No. 0 tens group 202, that the beam of tube, I I2 engages the No. 1

anode I36 while the scanning beam is passing over the No. 1 tens group, and similarly for theremultiplier. I39, which supplies a wave of the increased frequency to the phase divider I00, which in turn supplies its energy to the quadrature coils of thetube Il2. Y r Finally the switching beam ofthe unitstube I I3 is driven at ten times the speed of tube I I2 by current supplied through the frequency multiplier HI and phase divider I02 to the quadrature coils of the tube H3- Thus the synchronous relation between the tube H3 and the scanning device I03 is such that the beam of tube I I3 passes from one anode to the next eachtime the scanning beam moves from one lamp image to the next. More specifically, as the scanning beam passes over the ten successive image positions in any group of tens in any hundreds row the beam of the tube I I3 passes synchronously over its ten anodes. t

The purpose of the four switching tubes III), III, H2 and H3 is to operate a register mechanism I03 to register therein the thousands, hundreds, tens and units digits of the particular line corresponding to a lighted lamp in the field I02. Accordingly. the mechanism I03 is equipped with four digitregisters, two of which, the thousands and units registers I00, and I05, are illustrated. The register I00. comprises a series of ten discharge tubes I06, I01. and associated relays I08,

maining tens groups in any hundreds row. in any thousands group; The requisite speed for the beam of tube H2 is obtained by the frequency of relatively low resistance to ground. The cathbeam tube 3 and to the register relays I50 I 55.

And the same is true of the hundreds and tens registers not shown in the drawing.

A description will now be given of the operaq I23, I20and I25 of the switching tubes.

information for printing tions involved in the process of identifying a subscribers line. Assume for this purpose that the subscriber of line I00 wishes to make a toll call for which a ticket should be prepared to record the nature of the call and the charge therefor. When the subscriber initiates the call, the line finder F finds his line and extends it to the usual pulsing mechanism associated with the selector switch 8. The switch 8 and the switch B-I respond successively to the subscriber's dial I06 to extend his line to an idle trunk III outgoing in the desired direction. At any suitable time after the extension of the connection of the subscriber's line to the trunk IOI an idle registering mechanism I03 is associated with the connection. The

connection of the mechanism I03 with the con-' trolling circuit of the trunk MI is effected by a suitable connecting device I50. As the subscriber continues to dial the remaining digits of the wanted designation, these digits may be registered in the mechanism I03 where they are later used to control the operation of the switches in the offices beyond and also to furnish the necessary tablished through any suitablev connecting device that may be provided for that purpose. Also a circuitis closed from the source of energ I53 over conductor I60, connector I56 thence over the sleeve conductor through the switches S-I, S and F to the sleeve conductor III of the subscribers line I00. The circuit is completed from conductor I H through a condenser I62 to the lamp I63, which is individual to the line I00 and occupies the numerical position in the panel I02 corresponding to the number of the line. An image of the lightedlamp I63 is focussed by the lens system I05 in its proper elemental position on the image screen I00 of the device I03. It will be assumed for the Durpos'eof illustration that the number of the line I00 is 52483' The scanning device and'rotary beam switching tubes may be operating continuously or they may be started in any suitable manner under control of the register mechanism I03. While the scanning beam is passing Over the quiescent areas of the image screen I00 only virtual beams may be permitted to exist in the switching tubes H0, III, H2 and H3. This eifect is obtainedby selecting the voltage of battery I60 suchthat it is normally insufiicient to cause the creation oi an electron beam between the central cathodes of the rotary tubes and the outer anodes. Therefore, as the'scanning beam passes over unenergized areas of the screen I00 representing the unlighted lamps in the field I02 the'magnetic fields around the switching tubes IIO, III, H2 and H3 rotate in their synchronous relations with the scanning beam. but no real beams exist within these switching tubes. As soon, however, as the scanning beam reaches the energized image area representing the lighted lamp I63, a voltage is producedin the output circuitl" of the device I03. This voltage is amplified by a suitable amplifier I66, anda positive potential is applied over conductor I61 to the control. grids II5, This positive potential is sufllcient to permit the tubes to discharge, thus transforming the virtual beams the designation of the into real beams of electrons. At the particular instant when the switching beams becom real their positions are such that the beam of tube III impinges on the No. 5 anode lit, the beam of tube II I engages the No. 2 anode I09, the beam of tube II! engages the No. 4 anode I10, and the beam of tube I I2 encounters the No. 8 anode I1I.

If desirable the beams of the switching tubes may be continuously real but of insufllcient intensity to be effective except when the device I02 is scanning a sensitized image area. This eflect may be obtained in the obvious manner by adlusting the bias on the control grids I I5, I22, I24, I25, such that the beams are of low intensity until the device I02 finds the lighted lamp. And it will be understood that the invention contemplates the use of either a virtual beam replaced by a real beam when the lighted lamp is found or a real beam of low intensity replaced by one of high intensity when the lighted lamp is found.

When the switching tube IIO becomes eifecpurpose.

any suitable one of these may be used. For example, reference is made to the multiplier shown in Burton 1,917,921 of July 11, 1933. Similarly the phase dividers I20, I22, I40 and I42 used herein may be any of the numerous devices of the prior art which are suitable for the present One such device is shown in detail in .Fortescue 1,565,434 of December 15, 1925.

tive as above described, a circuit is closed from the negative pole of battery I64, conductor I'I2, I

hode II4 across the cathode beam to the ano e I02 thence through resistor I12 to ground.

Current flowing in the resistor I12 sets up a volt- In the alternative form 01' identifying mechanism illustrated in Figs. 3 and 4 a movable screen 200 is used for scanning the lamp field 202. The screen 200 is moved first in a vertical direction and then in a horizontal direction to scan an image of the field 202 which is focussed on the screen by a lens system I. The screen 200 is provided with horizontal and vertical slots 202 and -.204 respectively, which permit light to pass to light-sensitive element 205 when the screen reaches the horizontal and vertical positions corresponding to a lighted lamp in the field 202. Mechanism associated with the screen 200 and movable in synchronism therewith serves to de- 4 termine thefdecimal values of the digits of the age across the control gap of tube I41. There upon the tube I41 ionizes, and a circuit is closed from ground through the contact of relay I5I,"

battery I50, winding of register relay I45 through the main discharge gap of the tube I41 to ground. Register I42 operates in this circuit to register the thousands digit 5" of the line I00. At the same instant similar circuits ar closed across the electron beams of tubes III and H2 to cause the operation of corresponding registers to N8- ister the hundreds digit 2" and the tens digit "4 of the calling line. Also at the same instant a circuit is closed from battery I54, conductor I12, cathode I22 of the units tube II2, anode I" through the resistor I14 to ground. The voltage developed across the resistor I14 operates the tube I52, causing in turn the operation of register relay I55 to register the units digit "8 of the calling line I00. Thus the complete numbenof the calling line is detected and registered during the brief interval that the beam of the device I02 is resting on the image of the lighted lamp I52. An instant later the scanning beam passes to the next elemental image area which is unenergized, and the beams of the tubes IIO, III H2 and H2 revert to their virtual status and are ineffective to cause the operation of other registers.

After the number of the line has been registered in the mechanism I42, it is used in any suitable manner for causing the operation of a printer to print the number on the ticket which is being prepared for the call. This printer may be located in the controlling circuits I51 of the trunk MI, in which case the registered information in the mechanism I42 is transferred through the connector I58. After all necessary operations have been performed, the register mechanism I42 and the identifying mechanism are restored to their normal condition ready for subsequent use.

For more detailed information concerning the operation of identification systems reference may be had to the application of J. W. Gooderham, Serial No. 448,782, filed June 27, 1942.

The frequency multipliers I3I, I29 and I serve the purpose, as explained hereinbefore, of increasing the frequency by desired amounts. Many such devices are available in the art, and

engages the rack 2I2.

line represented by the lighted lamp. This mechanisrn is illustrated in detail in Fig. 3.

Referring now particularly to Fig. 3, the movable screen: 200 is supported by a horizontal shaft 200 to which it is attached for slidable movement thereon. The shaft 205 is secured at one end to a rack 201 which serves to translate the shaft in a vertical direction. For this purpose the opposite end of the shaft 205 is designed to slide freely in the guide member 205. The screen 200 is also attached to the vertical shaft 200 by means of guides 2I0 and 2 which permit the screen to slide freely on the shaft in a vertical direction. Like the shaft 206, the shaft 209' is secured at one end to a rack 2 I2 and at the other end is arranged to slide in the guide member 2I3.

The normal position of the screen 200 is, as shown in the drawings, in the upper left corner of the area indicated by the dotted square 2I4. In this position the horizontal slot 202 rests Just above the image area sit or the lamp field 202, and the vertical slot 204 lies just to the left of the area 2I6. The screen 200 is first driven downwardly along the shaft 209 by means of a motorlilywhich operates on the rack 201. In its downward movement the screen 300 causes the slot 205 toscan the horizontal lines of the image area 2I6. When the screen reaches its position in the lower left corner of the area 214 the slot 202 assumes a position below the image area 2I6, and the slot 204 is now opposite the image area and to the left thereof. The next step is to advance the screen 200 horizontally along the shaft 208 until it reaches a position in the lower right corner of the area 3I4. This is accomplished by operating the motor 3I9 which During the horizontal movement of the screen 200 the vertical slot 004 Y scans the vertical lines of the image area 2H5.

The vertical and horizontal scanning movements of the screen 200 are measured by digit switches 220, "I, 222 and 222. The brush of the switch 220 is connected directly to shaft 324,

which in turn is geared directly to the drivingmotor 2I8. Therefore, the brush at switch 320 moves over its ten position contacts in synchronism with the movement of the screen 200 from its upper to its lowermost position. These ten stationary contacts of the switch 220 correspond to the ten difierent values of the thousands digit of the lines, and they are connected correspondingly to the relays of the thousands register 323. The switch 3, which corresponds to the hundreds digit, is connected to the shaft 324 by gears 323 and 321 having a ratio such that the brush of switch 32i moves ten times as fast as the brush of switch 320. Thus the switch 32l moves in synchronism with the slot 303 over the ten hundreds horizontal rows of each thousand. The ten stationary contacts of the hundreds switch 32l are connected to the relays of the hundreds register 328. In a similar manner the motor 3| 3 is directly connected to the brush of the tens digit switch 322 which moves over its ten positions during the horizontal movement of the slot 304 over the image area 3l3. Also the brush oi the units switch 323 is driven through gears-323 and 330 at ten times the speed of switch 322 whereby the switch 323 is in synchronism with the vertical slot 304 as it passes over the units positions of each group of tens. The stationary contacts of the switches 322 and 323 are connected respectively to the relays of the tens and units registers 33l and 332.

The screen 300 is restored fromits operated position in the lower right corner of the square 3 to its normal position: by moving itfirst in avertical direction to the upper right corner of square 3 and then in a horizontal direction to its normal position as illustrated in Fig. 3 of the drawings. The vertical restoring movement of the screen is performed by a motor 333 which acts on the rack 301, and the horizontal restor- 'ing movementis performed by a motor 334 acting on the rack 3|2.

i The detailed operationof the scanning system shown in Fig- 3 will now be described. Assume that a circuit is closed for lighting the lamp 335. in the field 302. The energizing'circuit of the lamp 335 also includes thewinding of the relay 333 which operates and closes a circuit from battery through the winding of relay 331, contact of relay 333 to ground through the contacts 338 intheir normal position. Relay 33'! operates and locks ina circuit from battery through its winding and contact to ground through the contacts 333 in their normal position. Relay v331 also closes an obvious circuit for the motor 3 |3 which operates to drive the screen 300 in its downward scanningvmovement and also to rotate the thousands and hundreds digit switches 320 and 32l. As soon as'the screen 300 leaves its normal position, the contacts 333 shift to their off-normal position and open the operating circuit of relay 331. ,Durlng the downward movement of the screen 300 the light slot 303 encounters the image of the lighted lamp 335, and light passes through the slot to the photoelectric cellz305. The energy thus produced by the cell 305 is amplified by an, amplifier 340, and current ilows inthe output circuit of theamplifler over conductor 34! through the outer armature and back contact of relay 342, conductor 343 to the brushes of; switches 320 and 32| and over the segments on which these brushes are standingto the corresponding relays .of the respective thousands and hundreds registers 325 and 328.. As soon as the slot 303 passes by the image of the lighted lamp,

3". In the ofl-normal position of the contacts 333 an obvious operating circuit is closed for relay 342, which operates and locks to the contacts 344 in their normal position. Relay 342 closes a circuit for motor 3", which now drives the screen 300 in a horizontal direction and rotates the brushes of the switches 322 and 323. During its" initial movement, screen 300 disengages the contacts 333 permitting them to restore to their normal position thus opening the operating circuit of relay 342. As the screen 300 moves horizontally the light slot 304 encounters the image of the lighted lamp 335, and light passes through the slot to energize the photoelectric cell 303. The current flowing in the ouput of the amplifier 340 now passes over conductor 341 through the front contact of relay 342, conductor 343 brushes of the switches 322 and 323 to the corresponding relaysin the tens and units registers 33l and 332.

After the vertical slot 304 has completed the scanning of the im e area 3, the screen 300 engages the contacts 344 and, shifts them from their normal to their operated position. Contacts 344 open the locking circuit of relay 342, which releases and opens the driving circuit of the motor 3". Contacts 344 also close an obvious circuit for relay 348. which operates and locks to the contacts-341 in their normal position. Relay 346 closes an obvious circuit for motor 333, and the motonaots upon the rack'301 to drive the screen 300 in a vertical direction to the upper right corner of the square 3. During the initial movement of the screen 300 it disengages the contacts 344, permitting them to restore to their normal position to open the operating circuit of relay346. When the screen 300 is fully restored in the vertical direction, it engages contacts 341 circuit for relay 348, which locks to'the operated contacts 333. Relay 343 closes an obvious circuit formotor 334, and the motor drives the screen- 300 horizontally to the left. On the first movement of the screen'300 in its horizontal direction contacts-341 restore and open the energizing circuit of relay 348. Finally when the screen 303 reaches its normal position, it restores the conthe photoelectric cell 305 becomes ineffective, and

current ceases to flow in the output circuit of the amplifier 340. .r I

y Whenthe slot, 303 has passed over the entire image area 3l6,-the-screen 300 engages the contact springs 339 and shifts them from their normal to their operated position. Relay 331 now releases and opens the driving circuit of the motor device having a scannlngbeam and means for tacts 333 to open the locking circuit of relay 343 and the energizing circuit of the'motor 334. 'Thus the screen 300 has beenrestored to its normal position in the'horizontal "direction, and the tens and units registers 322 and 323 are now in their normal positions.

The operated'relays of the registers 323, 32 3, 33i and 332 may be lock'edin any well-known manner'and may serve as above explained to her of thecalling line.

What is claimedis: i

1. In a telephone system, in which'designations are assigned to the lines of a group on a decimal basis, each designation having a plurality of digital places, the-combination of a plurality of signal lamps individual respectively to the linesof said group, :said lamps being arranged in decimal order in a field of coordinate-rows; an electron cause the "printing of a, ticket to identify the numcausing said beam to scan said field of lamps in a definite order, switching beam devices, one for switching device having a beam position for each digit value of the corresponding place, means for driving the beams of said switching devices through the successive switching positions at such a rate with respect to the movement of said scanning beam that each switching beam occupies at any instant the switching position corresponding to the digit value of the signal lamp in said field which is being scanned at that instant by the scanning beam, a plurality of registers, one for each of said digital places, each register being capable of variable operation toregister any one of the digit values of the corresponding place, means for lighting any one of the lamps in said field to identify the particular line corresponding thereto, and circuit means interconnecting said switching devices and the corresponding registers and responsive to the respective switching beams for operating said registers to register the deslgnation of said particular line when the scanning beam scans the lighted signal lamp,

2. The combination in a signaling system, including a group of lines having designations assigned on a decimal basis, each designation having a plurality of digital places, of a plurality of signal lamps individual respectively to the lines of said group, said lamps being arranged in a field in decimal order, an electron device having a scanning beam and means for causing said beam to scan said held of lamps in a definite order, electron beam switching devices, one for each digital place in said designations, each switching device having a beam position for each digit value of the corresponding place, means for driving the beams of said switching devices in synchronous relation with said scanning beam, a plurality of registers, one for each of said digital places, each register being capable of variable operation to register any one of the digital values of the corresponding place, means for lighting any one of the lamps in said field, and circuit means interconnecting said switch devices and the corresponding registers and responsive to the respective switching beams for operating said registers to register the designation of the line corresponding to the lighted signal lamp.

3. The combination in a signaling system, including a group of lines having designations assigned on a decimal basis, each designation having a plurality of digital places, of a plurality of signal lamps individual respectively to the lines of said group, said lamps being arranged in a held in decimal order, an electron device having a scanning beam and means for causing said beam to scan said field of lamps in a definite order, electron beam switching devices, one for each digital place in said designations, each switching device having a beam position for each digit value of the corresponding place, means for driving the switching beams of said devices in synchronous relation with said scanning beam and at different relative speeds, the speed of each switching beam bearing a definite relation to the decimal values of the corresponding digital place, means for lighting any one of the lamps in said field to identify the particular line corresponding thereto, and means controlled by the beams of said switching devices and efiective when said scanning beam scans the lighted lamp in said field for registering the designation of the line corresponding to said lamp.

4. The combination in a signaling system of a group of lines having designations, each designseach digital place in said designations, each rality of lamps individual respectively to the lines of said group and arranged in decimal order, an electron device having a scanning beam and means for causing said beam to scan said lamps il in a definite order, switching tubes, one for each digital place of said designations, each tube having a series of positions representing the values of the digit in the corresponding place, means for causing a virtual beam to sweep over the in successive positions of each switching tube in synchronous relation with the movement of said scanning beam, means for lighting any one of the lamps in said group to identify the particular line corresponding thereto, means responsive to said is scanning beam and eifective when it scans the tion of the line corresponding to the lighted lamp.

5. The combination in a signaling system of a group of lines having designations, each designation having a plurality of characters, a plurality of signal elements individual respectively to the lines of said group, said elements being arranged in a field, a beam scanning device having a screen, means for producing on the said screen an image of said field of signal elements, a source of voltage of a given frequency for driving the beam of said so device at a given speed to scan its image field, a

plurality of switching tubes, one for each of the characters of said designations, each of said switching tubes having a series of positions and means for producing a beam of energy, each of said tubes having a driving means for causing the associated beam to move from one position to the next, frequency multipliers for increasing the frequency of the voltage from said source to difierent values, circuit means for applying the output energy of said frequency multipliers to the driving means of the respective switching tubes, said driving means responsive to the energy of the different frequencies for causing the associated beams to occupy the successive positions at different speeds, means for rendering any one of said signals efiective, and means controlled by said scanning device when its scanning beam scans the image of the effective signal element for rendering the energy beams of said switching tubes effective, and means responsive to the beams of said switching tubes for registering the designation of the line responsive to the effective signaling element.

6. In a signaling system, a group of lines havss ing designations, each designation having a plurality of digital places, a plurality of signal lamps individual respectively to the lines of said group, said lamps being arranged in a definite order in a field of coordinate rows, a screen having light 50 apertures therein, means for moving said screen to scan the lamps in said field, switches movable in synchronism with said screen, each of said switches having a series of positions representing the diflerent values of the digit in the corregg sponding place in said designations, means for lighting the lamp corresponding to any one of said lines, light-sensitive means responsive to light shining through the aperture in said screen when said screen reaches the position corresponding to the lighted lamp in said field, and means controlled by said light-sensitive means and said switches in the positions which they occupy when light from the lighted lamp through said aperture for establishing the desigtion having a plurality of digital places, a plunation of the corresponding line.

7. In a signaling system, a group of lines having designations, each designation having a. plurality of digital places, a plurality of signal lamps individual respectively to the lines of said group, said lamps being arranged in a definite order in a field of coordinate rows, a screen having horizontal and vertical light slots therein, means for moving said screen in both coordinate directions to scan said held of lamps with said light slots, a plurality of switching devices, one" for each of the digital places of said designations, means for driving said switching devices in synchronism with the movement of said screen in its vertical and horizontal directions while scanning said field of lamps, each of said switching devices having a series of positions representing the values oi the digit in the corresponding place, light-sensitive means responsive to light shining through the slots in said screen when said screen in its vertical and horizontal movements reaches the positions corresponding to a lighted lamp in said field, and means controlled by said light-sensitive means and said switching devices in the positions they occupy when said slots reach the position corresponding to a lighted lamp for establishing the designation of the line represented by such lighted lamp.

RALPH V. L. HARTLEY. 

